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Home > Products > Discrete Semiconductor Products > Transistors > FETs, MOSFETs > Single FETs, MOSFETs

STMicroelectronics LET9045S

Name: LET9045S
Brand: STMicroelectronics
SKU: LET9045S
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LET9045S

Manufacturer:: STMicroelectronics

Category:: Single FETs, MOSFETs

Package:: PowerSO-10RF Exposed Bottom Pad (2 Straight Leads)

Datasheet:: LET9045S.pdf

Description:: RF MOSFET LDMOS 28V POWERSO-10RF

Quantity:: RFQ Add To RFQ list

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Inventory:5,562

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Product details

Overview

LET9045S from STMicroelectronics is a common-source N-channel enhancement-mode lateral MOSFET RF power transistor in PowerSO-10RF (straight lead) package, rated for 80 V drain-source voltage, 9 A continuous drain current, and delivering 45 W output power with 17.5 dB gain at 960 MHz under 28 V supply. It features ESD protection (HBM Class 2), 1.2 °C/W junction-to-case thermal resistance, and is optimized for base station amplifiers.

For engineers reviewing the LET9045S datasheet, LET9045S pinout, LET9045S application, or LET9045S equivalent, key selection criteria include RF linearity at 960 MHz, thermal performance in SMD high-power layouts, gate drive compatibility with 2.0–5.0 V threshold, and compliance with JEDEC-qualified PowerSO-10RF mechanical standards.

Technical Context

This device operates in common-source configuration with fixed 300 mA quiescent drain current biasing, supporting broadband operation up to 1 GHz. Its lateral LDMOS structure delivers stable gain and high efficiency under mismatched load conditions (10:1 VSWR tolerance across all phase angles).

Dynamic performance is characterized at 28 V V_DD, 1 W input power, and 960 MHz frequency - yielding 45 W P_OUT, 65% drain efficiency, and 59 pF C_ISS. Static parameters include 80 V V_(BR)DSS, 1 µA I_DSS, and 2.5 mho transconductance at 3 A drain current.

Key Specifications

Parameter	Value and Actual Design Meaning
V(BR)DSS	80 V - Maximum safe drain-source blocking voltage before avalanche conduction
P_OUT @ 960 MHz	45 W - RF output power into 50 Ω load at specified bias and drive conditions
G_PS	17.5 dB - Power gain enabling single-stage amplification in macrocell BTS front-ends
R_thJC	1.2 °C/W - Enables direct thermal coupling to heatsink without intermediate interface layers
C_ISS	59 pF - Input capacitance defining matching network bandwidth and stability margins
V_GS(Q)	2.0–5.0 V - Gate threshold range allowing precise DC bias control for linear Class AB operation
ESD Rating	HBM Class 2 - Withstands 2 kV human-body-model discharge without parameter shift

Pinout & Package

LET9045S uses the PowerSO-10RF (straight lead) plastic package - ST's first JEDEC-approved high-power SMD RF package, featuring integrated heat slug and optimized RF grounding geometry. Dimensions comply with Table 9 (min/typ/max mm values), with critical stand-off and width tolerances ensuring reflow compatibility.

Pin/Terminal	Circuit Role	Design Meaning
Gate (Pin 1)	Control electrode	Receives RF input signal; requires impedance-matched 50 Ω trace and DC blocking capacitor
Source (Pins 2–5, 7–10)	Common reference node	Internally bonded multiple pins for low-inductance RF ground return path and thermal conduction
Drain (Pin 6)	Power output node	Connected to output matching network and heatsink via exposed metal slug; carries full RF output current

Key Features

Feature	Design Value
Common-source topology	Enables standard 50 Ω input/output impedance matching without external feedback networks
PowerSO-10RF package	JEDEC-qualified SMD footprint with integrated thermal slug for >70 W dissipation capability
10:1 VSWR tolerance	Survives antenna mismatch events without gain compression or device failure in deployed base stations
Lateral LDMOS process	Delivers superior linearity (65% drain efficiency) vs. vertical MOSFETs at 900 MHz band

Applications

Macrocell Base Station PA

Repeaters & Distributed Antenna Systems

Use Scenario: Final-stage RF power amplification in 900 MHz cellular infrastructure equipment operating continuously at ambient temperatures up to +70 °C.

IC Role / Device Role / Timing Role: High-efficiency, high-linearity RF power transistor in Class AB configuration driving 50 Ω antenna loads.

Use Value: 45 W output power and 17.5 dB gain reduce need for driver-stage amplification, lowering system BOM count and insertion loss.

Use Scenario: Bidirectional amplification in in-building coverage systems requiring stable gain over temperature and supply voltage variation.

IC Role / Device Role / Timing Role: Linear RF power amplifier core handling both uplink and downlink bands with minimal intermodulation distortion.

Use Value: 10:1 VSWR tolerance ensures reliable operation despite variable cable/connector impedances in distributed deployments.

Industrial RF Heating

Land Mobile Radio Transmitters

Use Scenario: Solid-state RF energy source in 915 MHz industrial heating systems requiring >10,000-hour MTBF and thermal stability.

IC Role / Device Role / Timing Role: Switching-mode RF power generator operating at fixed frequency with duty-cycled gate drive.

Use Value: 1.2 °C/W R_thJC enables passive heatsinking in enclosed enclosures, eliminating forced-air cooling subsystems.

Use Scenario: Final RF amplifier in portable and vehicle-mounted land mobile radios compliant with FCC Part 90 emission masks.

IC Role / Device Role / Timing Role: High-fidelity RF output stage delivering clean spectral emissions under pulsed transmission duty cycles.

Use Value: HBM Class 2 ESD rating protects against field-service handling damage during radio maintenance and installation.

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF power transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MRF6VP2450HR6	Higher P_OUT (50 W), GaN-on-SiC process, 28 V V_DD, but requires gate negative bias (–2.5 V)	Targeted at higher-frequency (2.1 GHz) macrocells; less suitable for 900 MHz legacy infrastructure due to gain roll-off	Select when upgrading to GaN-based PA stages with revised gate drive circuitry and thermal management
PD85004	LDMOS, same PowerSO-10RF package, 40 W P_OUT @ 960 MHz, lower gain (15.5 dB), 1.5 °C/W R_thJC	Designed for cost-sensitive repeater applications where 5 W output margin is acceptable	Choose for second-source qualification where reduced thermal performance is acceptable for lower-power tiers

Compared with MRF6VP2450HR6 and PD85004, LET9045S offers optimal balance of 45 W output, 17.5 dB gain, and 1.2 °C/W thermal resistance in a JEDEC-standard SMD package - making it the preferred choice for thermally constrained 900 MHz base station upgrades without redesigning gate drive or heatsink interfaces.

Availability

LET9045S is available at Aetrix Electronics and suitable for macrocell base station PA modules, repeater RF front-ends, and industrial RF heating systems requiring stable component supply across multi-year production cycles.

Supply support for LET9045S includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and communications markets.

The LET9045S belongs to ST's LdmoST plastic RF power transistor family, engineered specifically for high-reliability, high-efficiency broadband amplification in commercial and industrial wireless infrastructure.

FAQ

What is the recommended gate bias voltage for linear operation?

The LET9045S achieves optimal linearity at V_GS(Q) = 3.5 V, corresponding to 300 mA quiescent drain current. This bias point is verified in the datasheet's dynamic characterization section (Table 5) and maintains 65% drain efficiency while minimizing adjacent-channel power ratio degradation in 960 MHz LTE signals.

Can LET9045S be used in push-pull configuration?

No - the LET9045S is designed exclusively for common-source operation with single-ended input and output ports. Its internal pinout (separate gate, shared source, dedicated drain) and thermal layout do not support symmetrical push-pull mounting or complementary device pairing per the PowerSO-10RF mechanical specification.

Is the PowerSO-10RF package RoHS-compliant?

Yes - LET9045S is manufactured in ST's ECOPACK®-compliant PowerSO-10RF package, meeting EU Directive 2002/95/EC (RoHS) requirements. Lead-free soldering profiles and moisture sensitivity level (MSL 3) are fully documented in Section 2.4 and the ECOPACK® portal at www.st.com.

What is the maximum allowable case temperature during continuous operation?

The absolute maximum case temperature is 70 °C, as defined by the 79 W power dissipation rating at T_CASE = 70 °C (Table 2). Exceeding this temperature reduces safe operating area and risks thermal runaway; thermal design must ensure case temperature remains ≤70 °C under worst-case ambient and airflow conditions.

LET9045S Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: PowerSO-10RF Exposed Bottom Pad (2 Straight Leads)

Packaging:: Tube

Product Status:: Obsolete

Technology:: LDMOS

Configuration:: -

Frequency:: 960MHz

Gain:: 17.5dB

Voltage - Test:: 28 V

Current Rating (Amps):: 9A

Noise Figure:: -

Current - Test:: 300 mA

Power - Output:: 59W

Voltage - Rated:: 80 V

Grade:: -

Qualification:: -

Mounting Type:: -

Supplier Device Package:: PowerSO-10RF (Straight Lead)

LET9045S FAQ

1.How can I place an order for LET9045S through Aetrix?

Please submit a Request for Quotation (RFQ) for LET9045S on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for LET9045S reliable?

The price and inventory of LET9045S are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LET9045S is usually 5 days.

3.What payment methods are accepted for LET9045S?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LET9045S transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LET9045S?

LET9045S orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LET9045S order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for LET9045S?

For technical support, including LET9045S datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LET9045S requirements.

6.How does Aetrix verify that LET9045S is sourced from the original manufacturer or authorized distributors?

All LET9045S products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LET9045S meets industry standards.

7.What is the process for return or replacement of LET9045S?

All LET9045S units undergo pre-shipment inspection (PSI). If there is an issue with LET9045S, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The LET9045S part is unused and in its original packaging.

Return procedure for LET9045S:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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